Malware Threat To GNOME and KDE
commandlinegamer writes "foobar posted on his blog recently about 'How to write a Linux virus in 5 easy steps,' detailing potential malware infection risks in the .desktop file format used by GNOME and KDE. This is not a new threat, and it appears to still be a risk, as discussions in 2006 did not seem to come to any firm conclusion on how to deal with the problem." There's a followup on LWN.
Why do shortcuts need to have the ability to run code?
The shortcut only contains parameters for the path to the application and a list of parameters; it doesn't run any code itself. The problem is that the application can be (e.g.) /usr/bin/perl, and the parameters "-e 'perl code here'". Removing this ability would seriously impact the usefulness of the shortcuts.
The real issue is that the DEs are blindly trusting a non-executable file of unknown source to provide this information. The solution has already been suggested: turn all .desktop files into scripts (via a #! line, which is already valid comment syntax), mark them as executable, and have the DE run them like any other executable file. Non-executable .desktop files which link to applications would be displayed as usual, but would be treated as documents rather than launchers.
"The state is that great fiction by which everyone tries to live at the expense of everyone else." - Bastiat